Field of the Invention
The present invention relates to an ultraviolet sensor and an ultraviolet detecting device provided with the ultraviolet sensor.
Related Background Art
There are known ultraviolet (UV) sensors using compound semiconductors (e.g., cf. Japanese Patent Application Laid-open Publication No. H09-229763). The UV sensor described in the Publication No. H09-229763 includes a sapphire substrate and a compound semiconductor layer formed on the sapphire substrate. This LTV sensor has no sensitivity in a wavelength region longer than a detection target wavelength range in the UV region (e.g., the spectral region C of UV rays (UV-C rays)).
Another known UV sensor is one provided with first and second photodiodes having a spectral sensitivity in a range down to the UV region (e.g., cf. Japanese Unexamined Utility Model Application Publication No. S63-129837). In the UV sensor described in the Publication No. S63-129837, light is incident into the first photodiode, after passing through an optical filter that transmits the UV-A rays and UV-B rays. Light is incident into the second photodiode, after passing through an optical filter that transmits the UV-A rays but blocks the UV-B rays.